In cases of pancreatic insufficiency, pancrelipase and other pancreatic enzymes products (PEPs) can be administered to at least partially remedy the enzyme deficiency caused by various diseases affecting the pancreas, such as pancreatitis, pancreatectomy, cystic fibrosis, etc. The use of pancreatic enzymes in the treatment of pancreatic insufficiency is an essential part of the therapy of patients afflicted with cystic fibrosis. Without these supplements, patients become severely nutritionally impaired. This nutritional impairment can be life threatening if left untreated, particularly in the case of infants.
The drug substance pancrelipase is mainly a combination of three enzyme classes: lipase, protease and amylase, together with their various co-factors and co-enzymes. These enzymes are produced naturally in the pancreas and are important in the digestion of fats, proteins and carbohydrates. Pancrelipase is typically prepared from porcine pancreatic glands, although other sources can also be used, for example those described in U.S. Pat. No. 6,051,220, U.S. 2004/0057944, 2001/0046493, and WO 2006044529, each of which is herein incorporated by reference. The enzymes catalyze the hydrolysis of fats into glycerol and fatty acids, starch into dextrin and sugars, and protein into amino acids and derived substances.
Pancreatic enzymes show optimal activity under near neutral and slightly alkaline conditions. Under gastric conditions, pancreatic enzymes may be inactivated with a resulting loss in biological activity. Therefore, exogenously administered enzymes are generally protected against gastric inactivation and remain intact during their transit through the stomach and into the duodenum. Although it is desirable to coat pancreatic enzymes, uncoated preparations are also found in commerce. Pancreatic lipases are the most sensitive to gastric inactivation and are the most important single enzymes in the treatment of malabsorption. Lipase activity is typically monitored to determine the stability of an enzyme composition containing lipase.
After passage through the stomach, the enzymes should be released in the duodenum within 5-30 minutes, since digestion by pancreatic enzymes and absorption of the metabolites takes place primarily in the upper segment of the intestine, although digestion and absorption can take place throughout GI transit. Pancreatic enzymes have typically been coated with an enteric coating polymer, which protects the enzyme composition against the acidic environment of the stomach and then provides release of the enzyme in the intestine.
The conventional pancreatic enzyme preparations are intrinsically unstable and do not possess the shelf-life typically associated with approved pharmaceutical products for oral use. The activity of pancreatic enzyme preparations is typically determined based on the activity of lipase, which is one of the enzymes most sensitive to losing enzymatic activity during storage. Commercially available digestive enzyme compositions show a loss of lipase activity over time of up to about 35% or more. In order to compensate for the losses of enzymatic activity during storage and to ensure that the product provides the label-claimed potency at the end of the shelf life, manufacturers typically overfill the dosage forms from 5% to 60% and current USP specifications for Pancrelipase Delayed-Release Capsules allow for Pancrelipase equivalent to not less than 90% and not more than 165% of the labeled lipase activity.
In practice this means that patients and prescribers are unable to judge the dosage strength with accuracy, with the practical result that the appropriate dosage needs to be determined empirically for each new prescription. Patients with exocrine pancreatic insufficiency disorders rely on these drugs to provide the enzymes they need to digest food properly. If the label contains an inaccurate statement about a particular product's potency, then the patient is at risk for receiving too much or too little of the medicine.
Accordingly, it would be desirable to provide a stable digestive enzyme composition capable of maintaining the necessary activity for the expected shelf life of the enzyme preparation, without depending on overfilling the dosage form.